- Dactyl (Greek) – Little people and smith and healing spirits
- Daemon (Greek) – Incorporeal spirit
- Dahu (France, Switzerland and the north of Italy) – Similar to a deer or ibex; legs on one side of its body are shorter than on the other side
- Daidarabotchi (Japanese) – Giant responsible for creating many geographical features in Japan
- Daitengu (Japanese) – Most powerful class of tengu, each of whom lives on a separate mountain
- Daitya (Hindu) – Giant
- Dandan (Arabian) – Sea creature
- Danava (Hindu) – Water demon
- Daphnaie (Greek) – Laurel tree nymph
- Dark elf
- Datsue-ba (Japanese) – Old woman who steals clothes from the souls of the dead
- Dead Sea Apes (Islamic) – Human tribe turned into apes for ignoring Moses' message
- Ded Moroz (Russia) – A winter spirit who delivers gifts to children on New Year's Eve
- Deer Woman (Native American) – Human-deer hybrid
- Deity (Worldwide) – Preternatural or supernatural possibly immortal being
- Demigod (Worldwide) – Half human, half god
- Demons (Worldwide especially in Jewish, Christian, and Islamic mythology) - Evil spirits that torment mortals
- Dhampir (Balkans) – Human/vampire hybrid
- Diao Si Gui (Chinese) – Hanged ghost
- Dilong (Chinese) – Earth dragon
- Dip (Catalan) – Demonic and vampiric dog
- Di Penates (Roman) – House spirit
- Dipsa (Medieval Bestiaries) – Extremely venomous snake
- Dirawong (Australian Aboriginal) – Goanna spirit
- Diting (China) - Horned White Canine
- Di sma undar jordi (Gotland) – Little people and nature spirits
- Diwata (Philippine) – Tree spirit
- Djall (Albanian) – Devil
- Dobhar-chu (Irish) – King otter
- Do-gakw-ho-wad (Abenaki) – Little people
- Dokkaebi (Korean) – Grotesque, horned humanoids
- Dökkálfar (Norse) – Male ancestral spirits; the Dark Elves
- Dola (Slavic) – Tutelary and fate spirit
- Domovoi (Slavic) – House spirit
- Doppelgänger (German) – Ghostly double
- Drac (Catalan) – Lion or bull-faced dragon
- Drac (French) – Winged sea serpent
- Drakon (Greek) – Greek dragons
- Drakaina (Greek) – Dragons depicted with female characteristics
- Dragon (Many cultures worldwide) – Fire-breathing and (normally) winged reptiles
- Dragon turtle (Chinese) – Giant turtle with dragon-like head
- Drangue (Albanian) – Semi-human winged warriors
- Draugr (Norse) – Undead
- Drekavac (Slavic) – Restless ghost of an unbaptised child
- Drop Bear (Australian) – Large carnivorous koala that hunts by dropping on its prey from trees
- Drow (Scottish) – Cavern spirit
- Drude (German) – Possessing demon
- Druid
- Druk (Bhutanese) – Dragon
- Dryad (Greek) – Tree nymph
- Duende (Spanish and Portuguese) – Little people and forest spirits
- Duergar (English) – Malevolent little people
- Dullahan (Irish) – Headless death spirit
- Duwende (Philippine) – Little people, some are house spirits, others nature spirits
- Dvergr (Norse) – Subterranean little people smiths
- Dvorovoi (Slavic) – Courtyard spirit
- Dwarf (Germanic) – Little people nature spirits
- Dybbuk (Jewish) – Spirit (sometimes the soul of a wicked deceased) that possesses the living
- Dzee-dzee-bon-da (Abenaki) – Hideous monster
- Dzunukwa (Kwakwaka'wakw) – Child-eating hag